Improvement in adding-sticks



UNITED STATES PATENT OFFICE.

ROBERT F. ROCHE, OF UNITED STATES ARMY.

IMPROVEMENT IN ADDING-STICKS.

Specification forming part of Letters Patent No. 206,136, dated July 1li, l'd'S; application filed June 17, 1878.

.To all lwhom it may concern:

Be it known that I, ROBERT F. ROCHE, of the United States Army, stationed at Fort Foote, Maryland, have invented a new and Improved AddingStick; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing, forming part of this specification, in which- Figure l is a view of one side of the'addingstick cut longitudinally; and Fig. 2 is a view of the other half turned around so that its numbers face in the same direction as in Fig. 1.

My invention consists of a stick or ruler, made in the shape of a polygon or cylinder in cross-section, on the periphery of which numbers, from zero upward, are written consecutively in two spirals, whereby from certain movements of the thumb thereon, in accordance with a known key, a column of igures may be accurately added without mental eort, and without danger of forgetting the aggregate amount of a portion of a column it attention should be called from the work.

In the drawing, A represents the addingstick, made of an octagonal shape, and provided upon its periphery with two spirals, B and C, of figures ranging from zero upward, and winding around the stick side by side. These spirally-arranged figures are also arranged to coincide in rows longitudinally with the stick, and, as the ciphers of each spiral are upon opposite sides of the stick, the difference between the figures in the longitudinal rows will be four. There being two spirals of iigures, it will only be necessary to see one side of the stick, or four longitudinal rows of iigures, in adding any number-that is to say, there is no necessity for turning the stick around for the gures on the opposite side.

In operating the stick, the key explaining its use is as follows: To add 1, follow the spiral down one space; to add 2, follow the spiral down two spaces; to add 3, move obliquely down to the right in the tirst spiral below; to add 4, move one space down the longitudinal rows; to add 5, move one space obliquely to the left in the next lower spiral; to add 6, move two spaces obliquely to the left in the next lower spiral; to add 7, move obliquely one space to the right in the second lower spiral; to add 8, move two spaces down the longitudinal column; and to add 9, move obliquely to the left one space in tle second lower spiral, or three spaces to the right in the third lower spiral. Thus, in adding the column 2 7 4 6 3 5 9 l 8, we iind the first tigure (2) at the head of the stick; adding 7, we move obliquely to the right one space in the second lower spiral, making 9, at which the thumb is placed; adding 4, we move one space down the column, making 13, which is again held with the thumb; adding 6, We move obliquely two spaces to the left in the next lower spiral, making 19 adding 3, we move obliquely one space to the right in the next lower spiral, making 22; adding 5, we move one space obliquely to the left in the next lower spiral, making 27; adding 9, we move three spaces to the right in the three lower spirals, making 36 adding 1, we follow the spiral down one space, making 37; and adding 8, We move two spaces down the vertical column, making 45 as the total of the column.

By means of this stick it will be seen that the numbers are held as fast as added by the thumb, and, there being no tax of memory, what is ordinarily a mental operation is converted into a mechanical one, which not only greatly relieves the accountant, but facilitates the work, and reduces the possibility of errors.

As each gure iu a column is read the movement is made with the hand on the adder, which shows the totals as each figure is added.

The operation can be performed with either hand, and soon becomes so easy that the movement is made by habit when a ligure is read.

This instrument has the advantage that,hav ing no movable parts, and being all in one solid piece, it cannot get out of order.

The movements of the lingers for adding the same ligure are identical for the same figure always, a three being added to a seven in the same way as a tive or a nine by going with the eye or finger a certain direction and distance on the adder.

This method can be used in conjunction with mental addition, and is calculated to teach one to add mentally'. Addition can also be learned by it without slate or pencil.

The same instrument which is used as a spiral adder cau also be used for an oficeruler and a mensuling'sliek without much ndditiolml cost: or it could be impressed on pen cils, walking-sticks, &e.

It is an excellent device for teni-hing.;` ninnbers and addition to children nt home or in school.

As it ezln he nlzlde on n paper cylinder. it cnn be sold very cheaply in this form; also, colors cnn be used to further simplify the movements on the adderfor example, usine; three colors, so that 3, di, or il eould he udded without change of color.

This instrument van also be used :ls n tallystiek, for which purpose it is speciallyconvenient, als several things` cnn beeounted on it nt 

